The invention relates generally to the measurement of the loft time, power absorbed and speed of a vehicle relative to the ground. Such measurements are particularly useful in sporting activities like skiing, snowboarding and mountain biking where users desire information relating to their speed and/or loft, or xe2x80x9cairxe2x80x9d time.
It is well known that many skiers enjoy high speeds and jumping motions while traveling down the slope. High speeds refer to the greater and greater velocities which skiers attempt in navigating the slope successfully (and sometimes unsuccessfully). The jumping motions, on the other hand, include movements which loft the skier into the air. Generally, the greater the skier""s speed, the higher the skier""s loft into the air.
The interest in high speed skiing is apparent simply by observing the velocity of skiers descending the mountain. The interest in the loft motion is less apparent; although it is known that certain enthusiastic skiers regularly exclaim xe2x80x9clet""s catch some airxe2x80x9d and other assorted remarks when referring to the amount and altitude of the lofting motion.
The sensations of speed and jumping are also readily achieved in other sporting activities, such as in mountain biking. Many mountain bikers, like the aforementioned skiers, also crave greater speeds and xe2x80x9cairxe2x80x9d time.
However, persons in such sporting activities typically only have a qualitative sense as to speed and loft or xe2x80x9cairxe2x80x9d time. For example, a typical snowboarding person might regularly exclaim after a jump that she xe2x80x9ccaughtxe2x80x9d some xe2x80x9cbig sky,xe2x80x9d xe2x80x9cbig airxe2x80x9d or xe2x80x9cphat airxe2x80x9d without ever quantitatively knowing how much time really elapsed in the air.
There are also other factors that persons sometimes assess qualitatively. For example, suppose a snowboarder goes down a double-diamond ski slope while a friend goes down a green, easy slope. When they both reach the bottom, the double-diamond snowboarder will have expended more energy than the other, generally, and will have worked up a sweat; while the green snowboarder will have had a relatively inactive ride down the slope. Currently, they cannot quantitatively compare how rough their journeys were relative to one another.
It is, accordingly, an object of the invention to provide apparatus and methods for determining the xe2x80x9cairxe2x80x9d time of participants in sporting activities such as skiing and mountain biking.
It is another object of the invention to provide apparatus and methods for determining the speed of participants in sporting activities such as skiing and mountain biking.
It is yet another object of the invention to provide improvements to sporting devices which are ridden by sporting participants, and which provide a determination of speed and/or loft time of the device.
Still another object of the invention is to provide apparatus and methods for determining the amount of xe2x80x9cpowerxe2x80x9d or energy absorbed by a person during sporting activities.
These and other objects of the invention will become apparent in the description which follows.
The following U.S. patents provide useful background for the invention and are herein incorporated by reference: U.S. Pat. No. 5,343,445; U.S. Pat. No. 4,371,945; U.S. Pat. No. 4,757,714; U.S. Pat. No. 4,089,057; U.S. Pat. No. 3,978,725; and U.S. Pat. No. 5,295,085.
The invention concerns the detection and display of loft, or xe2x80x9cairxe2x80x9d time and/or speed of vehicles such as sporting vehicles, including skis, bikes, and snowboards. The invention thus provides a visual and quantitative measure of how much xe2x80x9cairxe2x80x9d time and, in certain aspects, how fast a user moves in a particular activity.
The invention provides, in one aspect, apparatus for determining the loft time of a moving vehicle off of a surface. A loft sensor senses a first condition that is indicative of the vehicle leaving the surface, and further senses a second condition indicative of the vehicle returning to the surface. A microprocessor subsystem, e.g., a microcontroller, determines a loft time that is based upon the first and second conditions, and the loft time is thereafter displayed to a user of the apparatus by a display, e.g., a LCD or LED display. Preferably, a power module such as a battery is included in the apparatus to power the several components. In addition, a housing preferably connects and protects the microprocessor subsystem and the user interface; and further such that the housing is attachable to the vehicle.
According to another aspect, the invention includes memory for storing information representative of at least one of the following: (i) the first and second conditions, (ii) the loft time, (iii) a speed of the vehicle, (iv) successive records of loft time, (v) an average loft time, (vi) a total loft time, (vii) a dead time, (viii) a real activity time, and (ix) a numerical ranking of successive records.
One preferred aspect of the invention includes a speed sensor, connected to the microprocessor subsystem, which senses a third condition that is indicative of a velocity of the vehicle. In this aspect, the microprocessor subsystem includes means for converting the third condition to information representative of a speed of the vehicle. Accordingly, the apparatus provides a user with both loft time, e.g., xe2x80x9cairxe2x80x9d time, and a speed of the vehicle.
In yet another aspect, the display of the invention can display selective information, including one or more of the following: the loft time; a speed of the vehicle; a peak loft time; an average loft time; a total loft time; a dead time; a real activity time; an average speed; an indication that loft time is being displayed; an indication that speed is being displayed; an indication that dead time is being displayed; an indication that real activity time is being displayed; successive records of loft information; successive records of speed information; a distance traveled by the vehicle; a height achieved by the vehicle off of the surface; and an indication of a number of a successive record relative to all successive records.
In still another aspect, the invention includes a user interface for providing external inputs to the apparatus, including one or more of the following: a start/stop button for selectively starting and stopping the acquisition of data by the apparatus; a display-operate button for activating the display means selectively; a speed/loft toggle button for alternatively commanding a display of loft time information and speed information of the vehicle; means for commanding a display of successive records of loft time information selectively; means for commanding a display of successive records of speed information selectively; means for commanding a display of information corresponding to average loft time; means for commanding a display of information corresponding to average speed; means for commanding a display of total loft time; means for commanding a display of dead time; means for commanding a display of distance traveled by the vehicle; means for commanding a display of height achieved by the vehicle off of the surface; and means for commanding a display of real activity time. Preferably, the microprocessor subsystem of the invention includes a clock element, e.g., a 24-hour clock, for providing information convertible to an elapsed time. Accordingly, the subsystem can perform various calculations, e.g., dead time, on the data acquired by the apparatus for display to a user.
In another aspect, the loft sensor is constructed with one of the following technologies: (i) an accelerometer that senses a vibrational spectrum; (ii) a microphone assembly that senses a noise spectrum; (iii) a switch that is responsive to a weight of a user of the vehicle; (iv) a voltage-resistance sensor that generates a voltage indicative of a speed of the vehicle; and (v) a plurality of accelerometers connected for evaluating a speed of the vehicle.
In a preferred aspect, the loft sensor of the invention senses a spectrum of information, e.g., a vibrational or sound spectrum, and the microprocessor subsystem determines the first and second conditions relative to a change in the spectrum of information. Further, the microprocessor subassembly interprets the change in the spectrum to determine the loft time.
For example, one aspect of a loft sensor according to the invention includes one or more accelerometers that generate a vibrational spectrum of the vehicle. In such an aspect, the first and second conditions correspond to a change in the vibrational spectrum. By way of another example, one loft sensor of the invention includes a microphone subassembly that generates a noise spectrum of the vehicle; and, in this aspect, the first and second conditions correspond to a change in the detected noise spectrum. Because these spectrums are influenced by the particular activity of a user, e.g., standing in a ski line, a microprocessor subsystem of the invention preferably includes means for assessing boundary conditions of the spectrum and for excluding certain conditions from the determination of loft time. Accordingly, if a skier is in a lift line, such conditions are effectively ignored. One boundary condition, therefore, according to an aspect of the invention, includes an elapsed time between the first condition and the second condition that is less than approximately 500 ms; such that events that are within this boundary condition are excluded from the determination of loft time. One other boundary condition, in another aspect, includes an elapsed time between the first condition and the second condition that is greater than approximately five seconds; such that events that are outside this boundary condition are excluded from the determination of loft time. Because these boundary conditions are important in the aspects of the invention which utilize a spectrum of information, the apparatus preferably utilizes a user interface for providing selective external inputs to the microprocessor subsystem and for adjusting the boundary conditions selectively.
In still another aspect of the invention, the microprocessor subassembly includes means for determining a pitch of the spectrum by determining a best-fit sine wave to a primary frequency of at least part of the spectrum and means for correlating the pitch to a vehicle speed. Accordingly, the invention can detect spectrum information and correlate that information to a speed of the vehicle. Typically, a higher pitch frequency corresponds to a higher vehicle speed and a lower pitch frequency corresponds to a lower vehicle speed. However, in another aspect, the selected pitch frequency can be calibrated relative to a selected vehicle and speed.
The invention also provides, in another aspect, means for storing information including look-up tables with pitch-to-speed conversions for a plurality of vehicles. This is useful because different vehicles have different associated noise and/or sound spectrums associated with the vehicle. Accordingly, the invention in this aspect includes memory for storing the respective calibration information of the different vehicles (typically in a look-up table format) so that a user can utilize the invention on different vehicles and still determine speed accurately. Specifically, a particular pitch is associated with a particular speed for a particular vehicle; and that association is selectively made by the user.
The vehicles which are preferably used, according to the invention, include (i) a snowboards, (ii) snow skis, (iii) water skis, (iv) skis for ski jumping, and (v) skis for ski flying. However, in certain aspects of the invention, a human vehicle can be used; although the processing power required to accurately process speed and/or loft information in this aspect is significantly increased.
In several aspects of the invention, the microprocessor subassembly includes one or more of the following: means for selectively starting and stopping the acquisition of data by the apparatus; means for responding to an external request to activate the display means; means for responding to an external request to alternatively display the loft time and a speed of the vehicle; means for calculating a speed of the vehicle; means for responding to an external request to display successive records of loft time information; means for responding to an external request to display successive records of speed information; means for determining an average speed; means for determining a total loft time; means for determining a dead time; means for responding to an external request to display information corresponding to an average loft time; means for responding to an external request to display information corresponding to an average speed; means for responding to an external request to display a total loft time; means for responding to an external request to display a dead time; means for responding to an external request to display a distance traveled by the vehicle; means for responding to an external request to display a height achieved by the vehicle off of the surface; and means for responding to an external request to display a real activity time.
The invention also provides certain improvements to sporting vehicles of the type ridden by a user on a surface (e.g., sporting vehicle such as (i) snowboards, (ii) snow skis, (iii) water skis, (iv) skis for ski jumping, and (v) skis for ski flying). The improvements include, in one aspect, a speed sensor having (i) a voltage-measuring circuit including a pair of conductors arranged to contact the surface so that the surface is part of the circuit, and (ii) an electromagnet for selectively generating a magnetic field on the circuit, wherein a voltage generated by the circuit is proportional to a speed of the vehicle. In such an aspect, the microprocessor subsystem determines a speed of the vehicle that is based upon the voltage, and that speed is displayed to a user.
The invention also provides certain methodologies. For example, in one aspect, the invention provides a method for determining the loft time of a moving vehicle off of a surface, comprising the steps of: (1) sensing the vehicle leaving the surface at a first time; (2) sensing the vehicle returning to the surface at a second time; (3) determining a loft time from the first and second times, and (4) displaying the loft time to a user of the apparatus.
In still anther aspect, the invention provides a method of measuring the amount of xe2x80x9cpowerxe2x80x9d a user absorbs during the day. A motion sensor, e.g., a microphone or accelerometer, attaches to the vehicle, preferably pointing perpendicular to the top of the vehicle (e.g., perpendicular to the top surface of the snowboard) so that a measure of acceleration or xe2x80x9cforcexe2x80x9d jarring the user can be made. The data from the motion sensor is integrated over a selected timexe2x80x94e.g., over the time of the skiing dayxe2x80x94so that an integrated measure of motion is acquired. By way of example, if the motion sensor is an accelerometer positioned with a sensitive axis arranged perpendicular to the top snowboard surface, then, through integration, an integrated measure of xe2x80x9cpowerxe2x80x9d is obtained.
Those skilled in the art should appreciate that the measure can be converted to actual power or similar unitsxe2x80x94e.g., watts or joules or ergs or Newtonsxe2x80x94though the actual unit is not as important as having a constant, calibrated measure of xe2x80x9cpowerxe2x80x9d for each user. That is, suppose two snowboarders have such motion sensors on their respective snowboards. If one person goes down a green slope and another down a double-diamond, then the integrated value out of the double-diamond snowboarder will be greater. The units are therefore set to a reasonably useful value, e.g., generic power xe2x80x9cUNITS.xe2x80x9d In one aspect, the power units are set such that a value of xe2x80x9c100xe2x80x9d indicates a typical snowboarder who skies eight hours per day and on maximum difficult terrain. At the same time, a snowboarder who rides nothing but green beginner slopes, all day, achieves something far less, e.g., a value of xe2x80x9c1xe2x80x9d. In this manner, average skiers on blue, intermediate slops will achieve intermediate values, e.g., xe2x80x9c20xe2x80x9d to xe2x80x9c50xe2x80x9d. Other scales and units are of course within the scope of the invention.
The measure of power according to the invention thus provides significant usefulness in comparing how strenuous one user is to another. For example, suppose two users ski only blue, intermediate slopes with the exact same skill and aggressiveness except that one user chooses to sit in the bar for three hours having a couple of cocktails. At the end of an eight hour dayxe2x80x94providing the power sensor is activated for the whole dayxe2x80x94the skier who skied all eight hours will have a power measurement that is 8/5 that of his cocktail-drinking companion. They can thereafter quantitatively talk about how easy or how difficult their ski day was. As for another example, suppose a third friend skis only double-diamond slopes and he takes four hours out to drink beer. At the end of the day, his power measure may still be greater than his friends depending upon how hard he skied during his active time. He could therefore boastxe2x80x94with quantitative power data to back him upxe2x80x94that he had more exercise than either of his friends even though he was drinking half the day.
The measure of air time, according to the invention, can also be used in a negative sense. That is, speed skiers try to maintain contact with the ground as air time decreases their speed. By monitoring their air time with the invention, they are better able to assess their maneuvers through certain terrain so as to better maintain ground contact, thereby increasing their time.
The measurement of air, speed and power, in accord with the invention, is preferably made via a sensor located on the vehicle, e.g., on the snowboard or ski on which the person rides. As such, it is difficult to see the sensor; so in one aspect the invention provides an RF transmitter in the sensor and a watch, with an RF receiver, located on the wrist of the person. The dataxe2x80x94e.g., air, power and speedxe2x80x94is transmitted to the person for easy viewing on the watch. In still other aspects, a memory element in the watch provides for storing selected parameters such as successive records of speed, air and power, or the average xe2x80x9cpowerxe2x80x9d spent during the day.
The invention is next described further in connection with preferred embodiments, and it will be apparent that various additions, subtractions, and modifications can be made by those skilled in the art without departing from the scope of the invention